Electronic Counter-Counter Measures Potential of a Noncoherent FH/MFSKCommunications System Under Conditions of Worst Case Hostile Electronic Counter Measures and Fading Channels

摘要

This thesis investigates the performance degradation resulting from multitoneinterference of orthogonal, noncoherent, frequency-hopped, M-ary frequency-shift keyed receivers (FH/MFSK) where the effect of thermal and other wideband noise is not neglected. The multiple, equal power jamming tones are assumed to correspond to some or all of the possible FH M-ary orthogonal signaling tones. Furthermore, the channel is modeled as a Ricean fading channel, a possibility precluded when thermal noise is neglected. Both the signaling tones and the multiple interference tones are assumed to be affected by channel fading. Both band and independent band multitone interference are considered. Performance is evaluated by obtaining a union bound on the probability of bit error, and receiver performance is compared with exact results for band multitone interference of a noncoherent FH/MFSK receiver under comparable circumstances. Except for the case of Rayleigh fading of the signal, the union bound is very tight for those cases that can be compared with exact results. The advantages of the union bound approach are twofold. First, the union bound approach yields a solution that is far less computationally intensive than that obtained with the exact approach. Second, the union bound approach allows numerical results to be obtained for interference conditions that are not amenable to exact analysis, such as independent multitone interference of FH/MFSK.